Moatiallita, I take you haven't played MGS2 then
So, uhh, reviews
MGS1 -> MGS3 -> MGS2
Note that qualitywise these are nigh-identical so the little things make up for this order
MGS1: It has the best story and atmosphere. The base of MGS gameplay was laid here and it hasn't considerably changed after this title. Great gameplay (like in them all) and (for psone) good graphics and atmosphere. The story makes it my favourite. Great cast of characters too. From bosses Psycho Mantis is unforgetable, same with The Raven, Sniper Wolf, Ninja etc. And in any way you viewit fist fight with Liquid Sanke on top of Metal Gear was badass.
That and it has nostalgic value like no other game for me minus Red Alert 2
MGS 2: Without doubt it was most anticipated PS2 title. It hones and smoothens the few gameplay falws original had and adds one big improvement - you can aim from first person with other guns in addition to sniper rifle. Yay! Like its predecessor it is defined by great gameplay, great characters and writing.
However MGS2 is also most flawed of the bunch - it has many ridiculously long cutscenes. And I mean really, really long cutscenes. And instead of Mr Badass himself Solid Snake we get to play as sissy prettyboy Raiden for most of the game (apart from Tanker Episode in the beginning of game). Though he didn't annoy me half as much he did some other people.
Boss fights weren't as good as in MGS1 (or in MGS3) but boss characters themselves were awesome. I share Tale's view that MGS2 has best Big Bad Evil Guy.
MGS2 for its flaws is still most intriguing and unique game of the bunch. In fact MGS2 is one of a kind and when arguing are games art or not MGS2 is one of the best weapons for the "yes it is art" faction. Like I said before it is twenty years ahead its time in some ways. Since I can't sum it up on my own:
I guess bolded parts might be reason why I like it so much
Anyway, enough on MGS2
MGS3:
As a game MGS3 is without doubt best of the series. It's gameplay is best, it has a lot better pacing, badass Snake returns (well, sorta) as main character and it has fantastic 60's atmosphere all over it.
If you simply want awesome game get MGS3, then other two. If you want something unlike any other game get MGS2, then other two. If you want to be cool get MGS1, then the other two